It is often desired to catheterize a patient with one or more catheters which are utilized to inject materials, such as radio-opaque materials, into various portions of the heart to thereby facilitate angiographic observation of various portions of that organ. For example, balloon tipped angiographic catheters (such as "Berman" angiographic catheters) are known having injection orifices for injecting radio-opaque materials, which orifices are located within about 1-2 cm of the tip. In particular, right ventricular angiographic catheterization may advantageously be used for the injection of a contrast agent into the right ventricular chamber for evaluation of contraction patterns of the right ventricle, assessment of tricuspid regurgitation and performance of biventricular angiography for study of interventricular septal motion. Unfortunately, to date, right ventricular angiography has been limited to a considerable extent due to the problems encountered with right ventricular irritability and/or catheter induced arrhythmias which substantially impair the desirability of right ventricular angiography.